REVIEW OF: Rönnqvist I et al, JAMA Netw Open 2021;4(7):e2116589

STUDY TYPE: Cohort study

We know electroconvulsive therapy (ECT) is effective for patients with severe depression, but does it reduce the risk of suicide in the months following initial inpatient treatment?

A recent Swedish cohort study examined this question by evaluating rates of suicide in the year after ECT. Subjects consisted of patients who had their first hospitalization for the treatment of moderate depression, severe depression, or severe depression with psychosis (n=11,050). Of this cohort, 5,525 received ECT and 5,525 did not. Non-ECT patients received standard treatment, which included pharmacotherapy with antidepressants and lithium. ECT was administered on average three times per week using unilateral electrode placement in most cases (87% of patients).

In the 12 months following hospital discharge, the rate of suicide was significantly lower among patients who received ECT compared to patients who received standard treatment (1.1% vs 1.6%; HR 0.72). ECT’s greatest suicide-reducing benefit was for patients aged 65+ years (p=0.001) and patients with severe depression with psychosis (p=0.001). The rate of suicide was also significantly lower among ECT-treated patients aged 45–64 (p=0.05). In contrast, ECT was not associated with a suicide risk reduction among patients aged 18–45 (p=0.5) or among patients with moderate depression (p=0.8).

Interestingly, all-cause mortality was significantly lower in the ECT group than in the non-ECT group within three months (0.7% vs 2.9%) and 12 months (1.7% vs 4.3%) of hospital discharge. The study did not include data about adverse events, such as medical or cognitive effects.

Carlat Take

This study gives us one more reason to use ECT for severely depressed patients as it appears to protect against suicide, especially for patients aged 45 years or more. Patients with severe psychotic depression and older patients (65+ years) seem to benefit the most.